/*
 * Sesame Inc.
 * Copyright (c) 2009 All Rights Reserved.
 */
package com.sesame.toolkit;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

/**
 * @author shubeta
 * 
 */
public class IdentifyCode {

    public Map generateImage() {

        // 在内存中创建图象
        int width = 60;
        int height = 20;
        BufferedImage image = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);

        // 获取图形上下文
        Graphics g = image.getGraphics();

        // 生成随机类
        Random random = new Random();

        // 设定背景色
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);

        // 设定字体
        g.setFont(new Font("Times New Roman", Font.PLAIN, 18));

        // 画边框
        g.setColor(new Color(33, 66, 99));
        g.drawRect(0, 0, width - 1, height - 1);

        // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
        g.setColor(getRandColor(160, 200));

        int x = 0;
        int y = 0;
        int xl = 0;
        int yl = 0;
        for (int i = 0; i < 155; i++) {
            x = random.nextInt(width);
            y = random.nextInt(height);
            xl = random.nextInt(12);
            yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }

        // 取随机产生的认证码(4位数字)
        String sRand = "";
        for (int i = 0; i < 4; i++) {
            String rand = String.valueOf(random.nextInt(10));
            sRand += rand;
            // 将认证码显示到图象中
            g.setColor(new Color(20 + random.nextInt(110), 20 + random
                    .nextInt(110), 20 + random.nextInt(110))); // 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
            g.drawString(rand, 13 * i + 6, 16);
        }

        // 图象生效
        g.dispose();

        Map identifyCode = new HashMap();
        identifyCode.put("image", image);
        identifyCode.put("rand", sRand);

        return identifyCode;
    }

    // 给定范围获得随机颜色
    int r = 0;
    int g = 0;
    int b = 0;

    private Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        r = fc + random.nextInt(bc - fc);
        g = fc + random.nextInt(bc - fc);
        b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }
}